The Einstein Tower in Potsdam, Germany was built by architect Eric Mendelsohn between 1920-1921. The tower, which researches solar magnetic fields, was inspired by Albert Einstein's study of relativity, but it's unknown whether Einstein approved of its design.

The Expressionist Einstein Tower, or Einsteinsturm, became fully operational in 1924. Einstein toured the facility, but — according to legend — his response to the tower was absolutely cryptic. Says Kuriositas:

Legend has it that Mendelsohn took Einstein on a tour of the tower and waited patiently for the nod of approval from the world famous scientist. And waited. And waited. Much later when Einstein met with the building committee it is said he whispered a single word – organic. To this day it is not known if this utterance was intended as approval or opprobrium.